Iraq’s most influential Shiite cleric has been quietly issuing religious edicts declaring that armed resistance against U.S.-led foreign troops is permissible — a potentially significant shift by a key supporter of the Washington-backed government in Baghdad.

The edicts, or fatwas, by Grand Ayatollah Ali al-Sistani suggest he seeks to sharpen his long-held opposition to American troops and counter the populist appeal of his main rivals, firebrand Shiite cleric Muqtada al-Sadr and his Mahdi Army militia.

So far, American officials have considered Sistani a “key stabilizing force in Iraq for refusing to support a full-scale Shiite uprising against U.S.-led forces or Sunnis — especially at the height of sectarian bloodletting after an important Shiite shrine was bombed in 2006.”